Some final thoughts, for the moment ....
Wrapping it up
This series started out entitled "effects of extreme thread wrapping...", but I have taken out the word extreme. Most of the old thread-wrapped flutes surveyed (indeed, all but one) showed considerable bore compression or strangulation. The test tenon was wrapped in a common polyester-cotton sewing thread, with considerably fewer turns than I had taken off the strangled cocuswood flute. The only extremes involved were the humidities of 25% and close to 100%, applied in quick alternation to accelerate the passing of time. For most of us, these are not uncommon conditions.
Perhaps it's appropriate to ask ourselves why, so long ago, makers of Boehm flutes, clarinets, and oboes shifted to cork, leaving only conical flutes string-wrapped. The simple, if painful, answer is that conical flutes were the cheap end of the market, and string is cheap.
It is now safe to conclude that it is clearly possible, indeed almost inevitable, to damage a tenon by wrapping it in thread, and subsequently exposing it to the rigours of weather and playing. Indeed, the question now becomes what can we do to ensure such damage doesn't happen? Unfortunately, the rigorous and numerous experiments needed to prove what is safe using multiple layers of thread might take dozens or even hundreds of tenons, and years, tens of years or even more! It may be misdirected energy to conduct such tests. Indeed, maybe we should be putting our energies in identifying newer, more appropriate materials and methods than either cork or thread.
Perhaps the most surprising discovery was that the free ends of the test tenon actually swelled in size, probably explaining why the three tenons on the strangled cocuswood flute jam on entry to their sockets. This means that we may be misinterpreting what the bores of old flutes originally looked like, and a more realistic test might be warranted to help guide our interpretations. This test would still take some time, because the thicker tenon attached to a real flute body would have much longer reaction time, but at least such a test would be achievable. Even so, it would still have to employ artificial aging techniques, or the results may not be available within a useful timeframe!
Even as I'm typing, I feel
another experiment coming on. The Richard Potter flute in the survey is
a total basket case at the moment, having lost many keys and blocks.
It's on my long-term list to try to save, but has no immediate hope.
I should carefully measure the LH section, strip the thread and subject
it to some deep humidity cycling to emulate the passage of the years.
But not attempt to steam and reform it as I did with the two strangled
flutes. The test would be aimed at finding out whether just removing the
constriction is enough, if given time and seasonal variation (either in
real-time or accelerated). If that doesn't work, it won't prevent me
from following the steaming and reforming approach later. I'll get
back to you when there's something to report....
Thanks to all those at Chiff & Fipple who took part in the lively debate, including the sceptics! It was useful to conduct this experiment in the light of public scrutiny, as it alerted me to the issues people found hard to accept. Hopefully I've now answered them!
As with any topic, there are the deniers who will never agree with any proposition, no matter how well proven. Some of these are just downright argumentative by nature. They deserve our compassion - life cannot be easy. Others clearly feel that their business interests are being threatened. If they put their business interests before the interests of their customers, they cannot expect our sympathy. Others quibble about details of the experimental approach. They would have criticised poor Fleming - he didn't predict penicillin after all, he merely discovered it. It is clearly possible for anyone sufficiently motivated to repeat or improve on the experiments conducted here. I'll happily advise them. Anyone not sufficiently motivated is not worth listening to.
To all of them, we simply pose the question: "If the thread didn't squash these tenons, what did?" Aliens perhaps? Come up with a plausible alternative scenario and we'll sit up and take notice.
Thanks to Neville Fletcher for clarifying the calculation of forces involved. Thanks also to a number of individuals from other flute email lists who have chipped in with the benefit of their specialist knowledge. I'll decline from naming any as I may forget some, but you know who you are!
Discussion of issues raised.
Discussions on Chiff & Fipple about earlier versions of this article became so heated the moderators felt obliged to lock the original and related threads a number of times. After discussion, we have agreed to try a "For Information Only" approach, in which I can announce any developments, but further discussion is discouraged. That seems to be working.
I'm happy to hear from anyone directly, and public discussion is available on any of these Internet fora:
Created: 23 January 2011; last updated 20 February 2011.